Quench-spark discharger.



L. DE FREST.

ouENH SPARK mscHARGgR. APPLICATION FILED APR-'24. 1915.

1,1 90,869. Patented July 11, y1916.

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UNITED STATES PATENT OFFICE.l

LEE DE FOREST, OF NEW YORK, N. Y., ASSIGNOR TO DE FOREST RADIO TELEPHONE AND TELEGRAPH COMPANY, OF NEW YORK, N.

Y., A CORPORATION OF DELAWARE.

QUENcH-SPARK DISCHARGER.

To all whom t may concern Be it known that I, LEE DE FOREST, a citizen of the United States, residing in the city of New York, county of Bronx, State of New York, have made a certain new and useful Invention in Quench Spark Dischargers, of which the following is a specification.

This invention relates to means Ifor quenching spark discharges in electrical discharge or high frequency circuits.

The object of the invention is to provide a quench spark discharger which is simple in construction,'efficient in operation, and economical to manufacture.

A further object of the invention is to provide an apparatus of the class referred to wherein thedanger of arcing across the spark gap is eliminated, thereby permitting exceedingly high currents to be used in connection therewith and to be eectively interrupted without destroying the spark gap or the spark gap discharger, or causing blisters on such surfaces the presence of which seriously interferes with the proper spatial relation of the surfaces, thereby impairing the proper functioning and operation of the system.

Other objects of the invention will appear on the accompanying drawing, and finally v pointed out in the appended claims.

Referring to the drawing,-Figure 1 is a view in end elevation showing one form of a quench spark discharger embodying my invention. Fig. 2 is a longitudinal sec ional view taken on the line 2-2, Fig. 1 and looking in the direction of the arrows.

The same part is designated bythe same reference numeral whereverl it occurs throughout the several views.

It is well known in the art of radio telegraphy and telephony that it is advantageous to use quench spark gaps of several parallel surfaces, or electrodes, separated by a distance very small relative to the linear dimensions of the surfaces.v For instance, it is common to employ a series of flat circular disks separated from each other by air gaps of several thousandths of an inch. It is also Specification of Letters Patent.

- corporating the above Patented July 11, 1916.

Application filed April 24, 1915. Serial No. 23,701.

well lmown in the art that it is highly advantageous to render these dielectric gaps or spaces between the electrodes air tight to prevent oxidization of the surfaces of the electrodes. It has been found necessary in practice to also provide cooling means' to prevent the air or gas dielectric from becoming ionized by the spark discharge thereacross.

It is among the special purposes of my present invention to provide a lquench spark discharger which may be used in connection with either alternating or direct currents indesirable features, and to provide means to completely eliminate any tendency to form an electric arc across the individual gaps.

A I have found that where a large amount of current is passed across a series of quench spark gaps the tendency of the dielectric to quench, or to periodically cut off or disrupt the passage of the current, is greatly increased if the sparking areas be subjected to certain arc eliminating gases or vapors other than, or in mixture with air or nitrogen.

have found that the vapor of carbon tetrachlorid is particularly efficacious in quenchin addition thereto,

ing sparkl discharges whether the spark dis-l charger is supplied from alternating or direct current sources. It is well known that a vapor of this compostion is effective for quenching combustion, posed to use such lightning arresters. I have discovered, however, that with certain arrangements hereinafter described, this or a similar vapor is quite an effective medium for quenching spark gap discharges.

Referring to the drawings, I have shown one construction embodying the principles of my invention wherein- 1 designates a vessel which may be of any shape, size or mater1al. In the construction shown, I employ a metal boxor envelop provided with cooling flanges or exterior ribs 2, either cast integral with the box or envelop or secured thereto. Contained in the box or envelop are the discharge electrodes 3 arranged in series. The end terminals 4, 5 are brought out of the two ends of the envelop 1 through bushings 6 which serve to insulate the terminals from the envelop 1. The end electrodes are electrically connected to their respective termicompletely closed,

and it has been prop a vapor 1n certain forms of -ployed to .insure the proper nals in 4any suitable or convenient manner.

The electrodes 3 are held orl supported in fixed relation to eachl otherin any suitable or convenient manner. I have shown one method wherein the rods, or flanges 7 of the electrodes 3 are secured to the envelop or boX l, but insulated therefrom by means of the insulating washers 8, lat envelop, and the insulating bushings 9 at the top, through which the flanges 7 pass.

rI`he liquid whose vapor is to serve as the spark quencher, may be any -suitable chemical which may be suitable for that purpose.

yAs hereinbefore stated, I have found liquid carbon tetrachlorid to behighly etlicient for that purpose, and is indicated at l0 at the bottom of the envelop 1,the lower edges of the electrodes being slightly above the upper level of the chemical.

If desired, and as shown, artificial cooling means, such as a fan 12, driven from anyl suitable or convenient source, may be emcooling of the spark discharger.

'Ihe heat from the discharge of the current)passing through the spark discharg'er is sufficient to vaporize the liquid, lor a portion thereof, contained within the envelop.

this respect.

In consequence, the vapor soV formed is diffused throughout the envelop and forms an eflicient and simple arc quencher between the electrodes as hereinbefore described.

It will be understood that if desired, the air may be exhausted from the envelop leaving therein only the liquid 10. I have found,

however, that this is not essential, and there fore I am not to be limited or restricted in While I have shown and described one embodiment of my invention, it will be understood that many changes in structure or details might readilyoccur to those skilld in the art without departing from the broad scope of my invention as defined in the claims.

the bottom of the" What I claim as new and useful and desire `to secure Yby Letters Patent, is,- 1

l. A spark gap device including a closed vessel, a dielectric liquid contained therein,

separated electrodes arranged therein andv provided with flanges immersed in said dielectric liquid, and means toutilize the heat of the electrodes to vaporize said liquid to quench the arc between said electrodes.

2. A high frequency spark discharger, comprising electrodes immersed 'in vapor of carbon tetraohlorid.

3. A series spark discharger comprising a plurality of electrodes subjected to a vapor of carbon tetrachlorid.

4. The combination with a quench spark gap of a dielectric containing vapor of carbon tetrachlorid for quenching the spark thereacross.

5. The combination with a quench spark gap of a mixture of air and vapor of carbon tetrachlorid for quenching the spark thereacross. v

6. In a spark discharger, the combination with a spark gap, of a dielectric vapor generated by the heat of the electrodes of said discharger for quenching the spark across said gap, and means independent of the discharger for cooling the same.y

. 7. In a spark discharger, the combination with a' spark gap, of a dielectric vapor generated by the heat of the electrodes of said discharger for quenching the spark across said gap, and a fan for maintaining said discharger cool.

S. In a spark discharger, the combination In testimony whereof I have hereunto set my hand von this 19th day of April A D. 1915.

v LEE DE FREST. 

